1. Field of the Invention
The present invention relates to contemporary tire mounting and inflating stations in which a tire is mounted to a wheel at a first station and then inflated at a second station. The present invention is more particularly related to a tire mounting and inflating apparatus in which both processes are carried out at a single station.
2. Description of the Prior Art
Vehicle assembly operations include sub-assembly operations for providing the required number of pneumatic vehicle wheels. Presently, these operations are performed by a plurality of work stations in which each detail of the operation is individually performed in sequence. Typically, the operations performed sequentially in contemporary tire mounting facilities are as follows.
A wheel is transferred to a first work station whereat a valve stem is provided on the wheel by a valve stemmer apparatus. The wheel is now prepared for transfer to the tire mounting apparatus.
Conventional tire mounting apparatus have dual roller conveyers, one each for tires and wheels, for taking the tires and wheels from a first location to an entry point in the tire mounting apparatus. Generally, the attitude of both the wheel and the tire is horizontal during the mounting and inflating processes.
The wheel is transferred via a first roller conveyer to a nest located on a pallet at an entry point of the tire mounting apparatus, whereat, frequently, a wheel soaper provides soaping of the rim of the wheel. At this same time a tire is transferred via a second roller conveyer to a tire conveyer at another entry point of the tire mounting apparatus located overhead the pallet, whereat a tire soaper provides a soaping operation on the bead of the tire. Generally, this operation is performed via a plurality of nozzles or by a wetted roller which rotates around the tire. The soap provides a lubricant during mounting of the bead of the tire onto the rim of the wheel as well as a film which can serve as a sealing agent between the rim and the bead. With soaping completed, the next step is "marrying" the tire to the wheel. This is accomplished by advancing the tire along the tire conveyer until a chute, or escapement, is encountered whereat the tire drops onto the wheel, the leading edge of the tire being low in relation to the rim of the wheel.
The pallet is now transferred to a tire mounting station. At the tire mounting station, "stuffers" push against the tread of the tire to ensure the leading edge of the tire is nestled between the upper and lower rims of the wheel. Actual mounting of the tire to the wheel is performed conventionally by one of two methods. In the first method, the wheel is locked in stationary position by clamping the wheel, then a rotating arm above the wheel rotates about the tire causing both upper and lower beads of the tire to slip over the upper rim of the wheel. In the second method, the tire and wheel move past two shoes, one shoe being located on each side of the wheel, the shoes force the tire beads to slip over the wheel rims from a given starting point as the wheel passes thereby.
The pallet is now transferred to a tire inflation station. At the tire inflation station the tire is inflated on the wheel to a first predetermined pressure. There are two conventional methods for carrying out this operation. In the first method, a large diameter steel tube descends so as to contact the tire sufficiently to separate the upper bead from the upper rim. The pallet nest for the tire and the wheel has a raised annular area which is air tight. Air under pressure is introduced into the steel tube causing the tire to internally pressurize. The steel tube is then raised, allowing the upper bead of the tire to mate with the upper rim of the wheel, thereby sealing the tire at a second predetermined pressure which is the operational pressure of the pneumatic wheel. In the second method, a first and second tube descend. The first tube descends to mate with the tire as described above with respect to the first method. The second tube, located within the first tube, descends to mate with the rim of the wheel. The space between the tubes is then subjected to air pressurization, and the tubes are then withdrawn to effect tire pressurization at the second predetermined value.
Conventional tire mounting devices may further include a tire and wheel matching operation, as well as a road simulation operation. In the tire and wheel matching operation, which occurs after tire mounting and before tire inflation, visual scanners are used to ascertain the eccentricity of the wheel and the tire. Then each are relatively rotated in order to achieve a best fit. In the road simulation operation, which occurs after tire inflation, the wheel is placed on rollers which cause the tire to be rotated in a manner indicative of driving so that the tire beads may find a final seating position on the wheel rims.
Examples of the aforesaid devices include the following patents. U.S. Pat. No. 4,547,945 to Lawson, dated Oct. 22, 1985, discloses a tire and wheel matcher having a sensing mechanism and a rotating mechanism. U.S. Pat. No. 3,658,152 to Mueller, dated Apr. 25, 1972, discloses a soaping apparatus incorporating a rotating roller for soaping the tire beads. U.S. Pat. No. 3,545,463 to Mueller, dated Dec. 8, 1970, discloses a tire mounting apparatus of the second type discussed above. U.S. Pat. No. 2,907,379 to Tuttle, dated Oct. 6, 1959, discloses another tire mounting apparatus of the second type discussed above. U.S. Pat. No. 2,665,747 to Harrison, dated Jan. 12, 1954, discloses yet another tire mounting apparatus of the second type discussed above. U.S. Pat. No. 2,470,534 to Thomas, dated May 17, 1949, discloses a tire mounting device of the first type discussed above. Great Britain Patent 2,085,818 to Goiseau, published May 2, 1984, discloses an automatic machine that fits a tire onto a wheel, where the wheel rim height is maintained at a predetermined value with respect to its conveyer apparatus. U.S. Pat. No. 3,978,903 to Mueller et al, dated Sept. 7, 1976, discloses a tire inflator apparatus of the second type discussed above. U.S. Pat. No. 4,183,392 to Kane, dated Jan. 15, 1980, discloses another tire inflator of the second kind discussed above. U.S. Pat. No. 2,910,117 to Lamerson, dated Oct. 27, 1959 discloses a tire inflator apparatus of the first type discussed above. U.S. Pat. No. 2,900,015 to Harrison, dated Aug. 18, 1959, discloses another tire inflator of the first kind discussed above. U.S. Pat. No. 3,461,938 to Mueller, dated Aug. 19, 1969, discloses a tire mounting and inflating system in which the operations are performed successively at different stations, the tire mounting apparatus being of the second kind discussed above and the tire inflation apparatus being of the second kind discussed above. U.S. Pat. No. 2,635,682 to Rerick et al, dated Apr. 21, 1953, and U.S. Pat. No. 2,488,376 to Clauser, dated Nov. 15, 1949, each disclose a tire and wheel assembly apparatus in which a locking ring is installed on the rim after the tire has been mounted.
All the aforesaid tire mounting and inflating devices suffer from significant disadvantages. The soaping station is located considerably upstream from the mounting station resulting in the soap liquids evaporating before the mounting operation commences, let alone concludes. A considerable amount of floor space must be dedicated to separate stations for soaping, mounting and inflating. Machine complexity is exacerbated by the need to transfer the wheel and tire from station to station, as well as the need to provide independent machinery for each of the separate operations performed at each station.
Clearly, what is required is a fast, efficient, reliable tire soaper, mounter and inflator apparatus that is integrated at a single station.